The treaty requires participating countries to cut down emissions from gases that trap heat in the atmosphere and, according to many scientists, are the cause of rising global temperatures and disrupted weather patterns.

Emissions of carbon dioxide, the byproduct of burning oil gas and coal, are to be reduced as a whole by 5.2% before 2012 compared with their 1990 levels. Other gases targeted are methane (mainly from agriculture), nitrous oxide, hydrofluorocarbons (HFCs), perfluorocarbons (PFCs) and sulpher hexafluoride.

Negotiations for the protocol originally began in Japan’s capital Kyoto on 12 December 1997, and it was finally ratified today when Russia gave its approval.

Environmental officials hailed the protocol as a historic step in the battle against global warming. ‘Today is a day of celebration and also a day to renew our resolve… to combat global warming,’ said Hiroshi Ohki, former Japanese environment minister and president of the conference that negotiated the protocol.

The US has controversially refused to be part of the agreement, even though it is the world’s largest emitter of such gases. Australia is the only other major developed country that has rejected Kyoto.